EMAP and Other Tools for Measuring Biodiversity, Habitat
Conditions, and Environmental Trends
Eric M. Preston and Christine A. Ribic
U.S. Environmental Protection Agency
Environmental Research Laboratory-Corvallis
Corvallis, Oregon
Abstract.-- Several research efforts that will contribute to
assessment and monitoring of neotropical migratory birds are
described, including: 1) the use of neotropical migrants in
the Environmental Monitoring and Assessment Program (EMAP) as
potential indicators of general environmental condition and
biodiversity; 2) EPA's Habitat/Biodiversity Research
Initiative to assess the comparative risks to biodiversity,
including neotropical migrant birds; and 3) other EPA
research to develop tools for assessing status and trends of
neotropical migratory birds at various spatial scales.
INTRODUCTION
In September, 1990, the U.S. Environmental Protection
Agency (EPA) Science Advisory Board (SAB) released a report
entitled: .Reducing Risk; Setting Priorities and Strategies
for Environmental Protection (U.S. Environmental Protection
Agency 1990). In this report, the SAB made several
recommendations about existing and emerging ecological
problem areas and the Agency's effectiveness in resolving
these problems. One broad recommendation was that EPA attach
as much importance to reducing ecological risks as to
reducing human health risk. Citing both ecological and human
welfare concerns, the SAB also strongly encouraged EPA to
address the loss of terrestrial and aquatic habitats. In
short, the SAB ranked habitat degradation and loss, species
extinction, and loss of biodiversity among the highest
environmental risks facing EPA and other governmental
agencies today.
Historically, EPA has assumed a secondary role in
habitat protection compared to several other federal
agencies. Now, habitat protection is a more common factor in
EPA actions. Current directions at EPA include an increased
emphasis on risk-based assessment of environmental problems
and nationwide monitoring of status and trends in ecosystem
extent and condition. These activities illustrate EPA's
movement towards a more comprehensive approach to
environmental risk management. In support, EPA's Office of
Research and Development is developing the methods and
technical information needed to address ecological risks to
habitat and biodiversity.
This paper will describe several research efforts that
will potentially contribute to assessment and monitoring of
neotropical migratory birds. These include: 1) the use of
neotropical migrants in the Environmental Monitoring and
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Assessment Program's (EMAP) as indicators of general
environmental condition and biodiversity; 2) EPA's
Habitat/Biodiversity Research Initiative to assess the
comparative risks to biodiversity, including neotropical
migrant birds; and 3) Other EPA research that will be
developing tools for assessing status and trends of
neotropical migratory birds at various spatial scales.
NATIONAL
EMAP Design as a Tool for Monitoring
Neotropical Migrants and Biodiversity
EMAP is a nationally integrated ecological research,
monitoring, and assessment program (Messer et al. 19915. Its
objectives call for monitoring the condition of the nation's
ecological resources and providing unbiased estimates of
status, extent, change, and trend with known confidence.
Building on the experience of previous surveys, the EMAP
sampling design incorporates a randomized systematic
triangular grid (fig. 1) to ensure random selection and
appropriate spatial distribution of samples {Overton et al.
1990, White et al. 1992). The base density results in
approximately 12,600 grid points in the conterminous United
States, The grid arrangement makes it easy to either
increase or decrease the grid density. The triangular grid
system establishes a hierarchical relationship among grid
densities, so those grid points from lower density grids are
subsets of higher density grids. Specific multiple factors
(e.g., 3-,4-, and 7-fold) are available to increase or
decrease the base grid density to accommodate the sampling
requirements for ecological resources of differing spatial
density.
Several features of the EMAP grid make it appropriate
for planning and conducting regional and national level
biological surveys. The design structure provides for good
spatial distribution of sampling sites and for repeated
sampling in time while maintaining the spatial distribution.
The spacing and timing of sampling may be adapted to the
characteristics of the resource. The probability basis of
the EMAP design provides quantitative inferences with known
confidence.
EMAP has organized sampling efforts around major
resource groups (e.g., surface waters, wetlands, forests)
that provide one focus for surveying of biodiversity, as
exemplified in pilot studies already underway on fish, bird,
and vegetation diversity. The resource group focus can be
supplemented by surveys conducted by taxonomic group (i.e.,
neotropical migrants) to capture wide-ranging and habitat-
transitional species. Finally, the EMAP design is based on a
global geometric model (White et al., 1992) and, therefore,
provides a basis for an international survey.
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Biodiversity as an Indicator of Ecosystem Condition
Two projects are underway within EMAP to evaluate
habitat and biodiversity metrics as indicators of ecosystem
condition.
EMAP - Forests
In the first, EMAP-Forests is sponsoring a project under
Thomas E. Martin, U.S. Fish and Wildlife Service, to develop
indices of biotic integrity (after Karr 1981) for forest
ecosystems. Dr. Martin is attempting to identify suites of
bird species that are clearly indicative of either
undisturbed ("healthy") or disturbed ("unhealthy") forests.
Forests are classified as healthy or unhealthy based upon the
total number of species and their abundances in each group
for a given forest stand. Thus, the approach is aimed at
identifying those tracts of forest that are suitable (i.e.,
healthy for forest-dwelling migratory birds as a group).
The work in progress is investigating indicators of bird
populations and a parallel set of indicators based on
vegetative characteristics of the breeding habitat. The
thrust of the work is to establish the relationships between
habitat characteristics and the health of the forest bird
communities on a site-by-site basis. Preliminary results
indicate that vegetative indicators based on breeding habitat
show promise in reflecting the health of breeding bird
communities. This means that the collection of vegetative
characteristics can be done in the EMAP framework in lieu of
collecting information directly on bird populations.
EMAP - Surface Waters
The second project is being supported by EMAP - Surface
Waters and conducted by Dr. Raymond J. O'Connor, University
of Maine. It is similar to the EMAP - Forests project in
that it is attempting to identify metrics of suites of bird
populations indicative of the condition of lake ecosystems.
Censuses of the birds of 20 selected lakes in New England
were conducted during the 1991 breeding season. Habitat
measurements were also made at census locations.
Individual bird species showed little evidence of
sensitivity to anthropogenic impacts. However, when species
were classified by guild membership, the relative abundance
of several guilds proved sensitive to anthropogenic impacts.
Two indicators based on the bird data were developed and were
shown to detect anomalous lakes (O'Connor, personal
communication). One indicator predicted species richness at
each lake on the basis of physical attributes of the lake,
with deviations from predicted values reflecting anomalous
conditions. The other characterized lakes as a multivariate
function of the bird guild composition, with the function
value altering with stressor intensity.
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Biodiversity as an Endpoint
This project, also conducted by Dr. O'Connor, is
currently investigating the usefulness of the U.S. Fish and
Wildlife Service Breeding Bird Survey (BBS) protocol for
developing indices of biodiversity within the EMAP sampling
frame. Specifically, the project is developing ways to add
habitat measurements to the Breeding Bird Survey routes and
to analyze the BBS data in conjunction with these habitat
characteristics. This project is investigating local and
landscape habitat characteristics and is developing guild
classifications for the bird species. In addition, the
project is addressing some of the biases in the Breeding Bird
Survey, such as the road-bias of the routes, by investigating
alternatives, such as checkplots, and comparing the results
to those from the BBS.
Habitat/Biodiversity Initiative
Habitat alteration and destruction with consequent
biological depletion are among the greatest ecological
threats facing the nation (U.S. EPA 1990). Three factors are
thought to contribute to the problem. First, habitat
modification may often be the inadvertent result of
independent and poorly coordinated land use decisions that
result in habitat fragmentation. This isolates certain
species in ever smaller patches of suitable habitat and
creates barriers to movement between patches. Second, the
cumulative effects of local habitat modification.and
contamination reduce the quality of remaining habitat
patches. Third, these factors in combination alter
competitive relationships and predator/prey relationships
within habitats. Invasive, introduced species then can
displace native indigenous species, with consequent loss of
native biodiversity in the landscape.
Along with other federal and state agencies, EPA shares
a responsibility for the conservation of natural resources
and protection of the environment. Implicit in many of EPA's
legislative mandates, and found throughout its regulatory
authorities, is the notion of maintaining natural
biodiversity. One of the problems facing federal agencies is
that habitat stewardship is divided among many land
ownerships, each with a different perspective on risks and
values. As stated by the Council on Environmental Quality
(1991) "Piecemeal management -- ignoring the interdependence
of parts of. any ecosystem that happen to be separated by
political boundaries or by lines of land ownership -- can
lead to environmental and biological decline." To stem
further loss of habitat and biodiversity, it is necessary to
develop a federal partnership that recognizes the complexity
of multiple-ecosystems, multiple-values and multiple-stresses
associated with landscape mosaics of interacting ecological
systems distributed among federal, state, and private
ownerships.
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In response, we are proposing a multi-agency,
collaborative project to develop the methods and data needed
to assess risks to biodiversity. We propose to categorize
and map the relative species diversity and landscape type
diversity of each of about 12,000 sampling units (hexagons)
based on the EMAP sampling grid covering the conterminous
United States (fig. 2). The process (fig. 3) will include
(1) compilation of The Nature Conservancy's detailed
vertebrate species distribution and attribute data for each
hexagon, (2) compilation of remotely sensed land
characterization data , (35 determination of whether low-cost
remote sensing data (Advanced Very High Resolution
Radiometry, AVHRR) that describe landscape types will be an
acceptable surrogate for habitat at the national scale, and
(4) analysis of the species and land characterization data by
different ecological weighting methods, spatial analyses,
multivariate statistical pattern analyses, and protection
optimization methods. This information, along with stressor
data compiled from existing databases, will be evaluated and
synthesized to quantify relative risks to biodiversity and
landscape types by region and landscape type. Overall
patterns that lead to high importance and vulnerability of
natural landscapes and biodiversity will be identified.
In completing an assessment of the risks to landscape
and biodiversity, methods of prioritizing the protection of
both wildlife and landscape types are needed. Any policy
recommendations must initially consider a variety of options
and the amount of habitat and diversity protected under each
option must be known.
Prioritization recognizes the need to establish a
sequence -of target areas for application of management and
regulatory resources. Prioritization in this study will be
done in two ways. First, individual species will be weighted
by a variety of factors that represent their contribution to
differing values associated with biodiversity. Such values
might include importance in ecosystem function and
sustainability, genetic "uniqueness", vulnerability to
habitat fragmentation, and conservation importance (rarity).
Second, individual landscape types, as represented by number
and proportion of the spatial areas of particular remotely
sensed classes, will be evaluated as a surrogate for
landscape structural diversity.
Prioritization will be implemented by ranking cells
according to the joint criteria of maximum coverage but
minimum redundancy in species or landscape type occurrence.
We will perform sensitivity analyses to examine the
robustness of methods of weighting, aggregation, and ranking.
Expected benefits include (1) establishment of baseline
conditions of species distributions and landscape types, (2)
comparative risk assessment of stressors that threaten
biodiversity, and (3) testing of methods that hold promise
for significantly reducing costs of habitat monitoring,
evaluation, and management. The project is designed to
complement the higher resolution analyses of the Fish and
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Wildlife Service's GAP Analysis Program by explicitly
relating the distribution of anthropogenic stressors to
biodiversity and landscape types through the risk assessment
process.
Although the program's objectives are national in scope,
several scientific issues will be addressed initially and
resolved in an integrated series of pilot projects in
different landscape types. The criteria used in selecting
areas for the pilot projects will include availability and
completeness of appropriate biological, landscape, and
stressor data bases? a variety of cover types representative
of those to be encountered in the national assessment; and
ability to support ongoing research in EMAP and the U.S. Fish
and Wildlife Service's GAP Analysis Project.
The pilot projects are being designed to address the
following research issues and questions:
o Is the AVHRR land classification (Loveland et al.
1991) an ecologically meaningful representation of
landscape diversity?
o Can vertebrate diversity be meaningfully associated
with landscape diversity?
o Will existing stressor data bases allow an adequate
characterization of risks to biodiversity?
The pilot projects will have somewhat different research
orientations due to differences in data availability, scale,
and issues being addressed. One or more of the following
activities will occur as appropriate:
o Vertebrate species will be allocated to hexagons.
In some cases rare plants and some invertebrates
will be allocated as well.
o AVHRR landscape representations will be compared to
GAP Thematic Mapper vegetation maps.
o Landscape and species data will be analyzed for
spatial pattern, type of diversity represented, and
interaction effects between the two kinds of data.
o Stressor data will be prioritized, analyzed for
allocation to the hexagon spatial framework, and
developed into a data base as feasible.
REGIONAL
EPA's Global Change Research Program has recently
awarded a competitive cooperative agreement to Dr. W. Carter
Johnson, South Dakota State University, to evaluate the
potential consequences of global climate change and other
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environmental factors on migratory waterfowl populations in
the glaciated prairie region of North America. The
investigators will be working in collaboration with related
research programs in the U.S. Fish and Wildlife Service, U.S.
Bureau of Reclamation, and the U, S. Geological Survey. Global
circulation models project a warmer and drier climate for
this region, and initial model simulations indicate that this
could cause a dramatic decline in habitat quality and
waterfowl production. The research will investigate the
major factors affecting waterfowl populations through
literature review, agency statistics, statistical analyses,
simulation model development, and remote sensing.
Simulations will enable assessment of the waterfowl resource
and its vulnerability to the singular effects of climate
change. A remote sensing protocol will be developed for
early detection of the climate change signal in prairie
wetlands.
WATERSHED
As a part of EPA's Midwest Agrichemical
Surface/Subsurface Transport and Effects Research Project
(MASTER), EPA is evaluating how changes in the composition
and quality of habitat types and their spatial arrangement
affect environmental quality, ecological processes, and
species composition and abundance. The Walnut Creek
watershed in Iowa, a watershed containing one of the U.S.
Department of Agriculture Management Systems Evaluation Areas
(MSEA) was selected for study.
The long-term goal of the terrestrial research is to
develop a land-use plan for the watershed that maximizes
ecological benefits to terrestrial flora and fauna^while
maintaining an acceptable level of agricultural production.
Among the major research objectives are: (1) development of a
landscape model for evaluating potential benefits to
terrestrial biota from alternative land uses, management
practices, and habitat manipulations without compromising
commodity yields, and (2) evaluation of the impact of
agrichemicals, other agricultural practices, and habitat
factors on terrestrial biota.
SUMMARY
The EPA is currently developing tools that will enable
managers to evaluate changes to biodiversity at national,
regional, and watershed scales. These tools are being
developed in cooperation with other federal agencies as well
as with universities and will provide a framework for risk
based assessment and management of habitat and biodiversity.
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ACKNOWLEDGEMENTS
We would like to acknowledge Ross Kiester, Denis White,
Thomas Loveland, Lawrence Master, J. Michael Scott, and
others who have contributed to EPA's Habitat/Biodiversity
Initiative. We would also like to thank the cited
researchers who graciously allowed us to reference their
unpublished research in progress.
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Figure 1. --The EMAP randomized systematic triangular grid
system.
Figure 2. --The EMAP grid as an organizing framework for
biodiversity, landscape, and stressor data.
Figure 3. --Analysis strategy for a synoptic national
assessment of comparative risk to biological diversity
and landscape types.
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Grid Density Enhancement
27km
base density
3-fold
4-fold
7-fold
Enhancement factors for increasing the base grid density.
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EMAP Hexagons
Class 1
B Class 2
U Class 3
D Class 4
TNC species occurrence data
AVHRR landscape types
Stressor data
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Analysis Strategy
Spec/es occurrence data
For each vertebrate species
(mammals, birds, reptiles,
amphibians, fish):
• taxonomy
* biological description
* conservation status
• economic attributes
* spatial distribution
• migration attributes
• habitat characteristics
• food habits
* phenology
Compute metrics;
* species richness
* functional diversity
• genetic diversity
• fragmentation
• conservation
Analyze spatial patterns:
• maps by region
• aggregate hexagons
• contour maps
Landscape type data
For each AVHRR land type:
• vegetation type
• land cover type
* greenness attributes
* climate attributes
* terrain attributes
• Omernik ecoregion
Compute metrics:
• composition
• dominance
* contagion
• fragmentation
Analyze spatial patterns:
• maps by region
* aggregate hexagons
• contour maps
Stressor data
Areal and point data:
* water quality
• toxics
• ag chemicals
• mining & forestry
* development
Evaluate and allocate
to hexagons or larger
units as appropriate
Analyze spatial patterns
Analyze joint patterns:
• classification
» ordination
* regression
Identify and prioritize
areas of concern
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ERL-COR-
TECHNICAL REPORT DATA
{fttatt rttd Imurucriont on the rtvent otfort eompttf
1. REPORT NO.
EPA/600/A-92/205
2.
a.
4. TITLE AND SUBTITLE
ft. REPORT DATE
EMAP and Other Tools for Measuring Biodiversit|i/p,ERFORMiNO ORGANIZATION CODE
Habitat ondiditons and Environmental Trends
7. AUTHORiS)
Eric Preston, Christine A. Ribic
S. PERFORMING ORGANIZATION REPORT NO.
». PERFORMING ORGANIZATION NAME AND ADDRESS
EPA, ERL-Corvallis, OR
10. PROGRAM CLEMENT NO.
11. CONTRACT/GRANT NO.
12. SPONSORING AGENCY NAME AND ADDRESS
US Environmental Protection Agency
Environmental Research Laboratory
200 SW 35th Street
Corvallis, OR 97333
13. TYPE OF REPORT AND PERIOD COVERED
Symposium Paper
14. SPONSORING AGENCY CODE
EPV600/02
is. SUPPLEMENTARY NOTES
1992. Proceedings: National Training Workshop on Status and
Management of Neotropical Migratory Birds.
16. ABSTRACT
Several research efforts that will contribute to assessment and
monitoring of neotropical migratory birds are described, including: 1)
the use of neotropical migrants in the Environmental Monitoring and
Assessment Program (EMAP) as potential indicators of general
environmental condition and biodiversity; 2) EPA's Habitat/Biodiversity
Research Initiative to assess the comparative risks to biodiversity ,
including neotropical migrant birds; and 3) other EPA research to
develop tools for assessing status and trends of neotropical migratory
birds a& various spatial scales.
KEY WORDS AND DOCUMENT ANALYSIS
DESCRIPTORS
b.lDENTIFIERS/OPEN ENDED TERMS C. COSATI Field/Group
biodiversity, neotropical, EMAP,
migratory
i«. DISTRIBUTION STATEMENT
Release to Public
1*. SECURITY. CLASS (Ttui Xtportl
Unclassified
21. NO. Of PAGES
12
20 SECURITY CLASS
Unclassified
2. PRICE
CPA r»rm 1220-1
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